The present invention relates to a process for reducing coke formation in organic compound conversion processes.
Fouling of catalysts and/or process equipment by coke is a major problem in high temperature organic compound conversion processes. Coke can cover active catalyst sites and plug catalyst pores, thereby reducing activity. In process equipment, it can build up on furnace tubes and reactors leading to heat transfer and pressure drop problems. Coking in some cases can be so severe as to completely plug the process with coke. While there are many methods of controlling coking such as careful selection of catalysts and plant metallurgy, application of low coking coatings, and/or the addition of steam or sulfur, coking still remains a major problem. Application of low coking coatings, often referred to as Metal Protection Technology (MPT) is taught in U.S. Pat. Nos. 5,866,743; 5,849,969; 6,019,943; 5,676,821; 5,593,571; 5,863,418; and 5,413,700 all of which are incorporated herein by reference. In some processes such as delayed coking or flexi-coking, coke is a by-product of the process that has a very low value. Clearly any method that can reduce the amount of coke formed would be very beneficial. The present invention provides such a method that can be used to minimize coking in a wide variety of processes and applications.
The present invention provides a process for reducing coke formation in organic compound conversion processes by the application of radio frequency electromagnetic radiation.
One embodiment of the present invention describes a process for suppressing the formation of coke during processing of a carbonaceous or organic material, comprising: applying electromagnetic radiation with a frequency below 300 MHz to the carbonaceous or organic material while heating said material to a temperature above 700xc2x0 F.
Another embodiment of the present invention involves a process for suppressing the formation of metal-containing coke on a catalyst which contains a coke forming metal, the process comprising applying electromagnetic radiation with a frequency below 300 MHz to a reaction chamber which contains a catalyst comprising a metal selected from the group consisting of Mn, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, and Cu, in contact with a carbonaceous or organic material at conditions suitable for converting the carbonaceous or organic material, to form a stream comprising hydrogen.
The present invention also describes a method for operating a fuel cell comprising:
contacting a carbonaceous or organic material in the presence of electromagnetic radiation having a frequency below 300 MHz with a catalyst at conditions suitable for reforming the hydrocarbonacous material to form a stream comprising hydrogen; and
converting at least a portion of the stream comprising hydrogen in a fuel cell to produce an electrical current.
In an alternative embodiment of the present invention a process for improving the properties of carbonaceous materials made by metal catalyzed processes above a temperature of 700 degrees F. by application of electromagnetic radiation to said process with a frequency of below 300 MHz is described.
Among other factors we have surprisingly discovered that application of electromagnetic radiation with a frequency of less than 300 MHz, and more preferably less than about 50 MHz with an electric field strength less than 5000 V/cm and more preferably less than about 1000 V/cm will suppress coking in high temperature organic containing compound conversion processes. In a preferred embodiment of the present invention, this technology suppresses metal catalyzed coking in high temperature hydrocarbon conversion processes, as well as in any high temperature process that utilizes, converts, or produces CO and/or CO2 where metal catalyzed coking is a problem. We have also surprisingly discovered that the application of electromagnetic radiation with a frequency of less than 300 MHz, and more preferably less than about 50 MHz with a field strength less than about 5000 V/cm and more preferably less than about 1000 V/cm will reduce the amount of coke formed in delayed cokers, flexi-cokers and resid fluidized-bed catalytic crackers. Furthermore this process can be used in conjunction with any of the other coke suppression technologies taught in the arts.
We have also surprisingly discovered that application of electromagnetic radiation with a frequency of less than 300 MHz, and more preferably less than about 50 MHz with an electric field strength less than 5000 V/cm and more preferably less than about 1000 V/cm can be used to alter or improve the properties of carbonaceous materials made by metal catalyzed processes.